Proteins morphology

Virus symmetry The nucleocapsids of viruses are constructed in highly symmetrical ways. Symmetry refers to the way in which the protein morphological units are arranged in the virus shell. When a symmetrical structure is rotated around an axis, the same form is seen again after a certain number of degrees of rotation. Two kinds of symmetry are recognized in viruses which correspond to the two primary shapes, rod and spherical. Rod-shaped viruses have helical symmetry and spherical viruses have icosahedral symmetry. 

How does the protein morphology or secondary structure change upon metal binding ... 

Barkhordarian H, Emadi S, Schulz P, Sierks MR (2006) Isolating recombinant antibodies against specific protein morphologies using atomic force microscopy and phage display technologies. Protein Eng Des Sel 19 497-502. 

Protein synthesis is essentially a translational process of messenger RNA which has been transcribed from the DNA template. The first reaction is the activation of amino acids by amino-acyl transfer RNA synthetases making use of ATP as an energy source, and the enzymes also attach the amino acid to transfer RNA to form amino-acyl transfer RNA. We have already seen that protein synthesis in plasmodia can be inhibited much further back along the chain, either at the folate co-factor level or during nucleic acid synthesis. It is obvious that interference with RNA transcription from DNA (or with DNA replication), or interference with the availability of essential amino acids, will also affect plasmodial synthesis of protein. Morphological studies of the effects of antimalarials on plasmodia support the occurrence of both modes of action for chloroquine, quinacrine, and quinine. 

Wool belongs to the family of proteins (qv) called keratins. However, morphologically the fiber is a composite and each of the components differs in chemical composition. Principally the components are proteinaceous, although wool cleaned of wax, suint, and other extraneous materials acquired during growth contains small amounts of Hpids (stmctural and free), trace elements, and, in colored fibers, pigments called melanin. 

In addition to effects on biochemical reactions, the inhibitors may influence the permeability of the various cellular membranes and through physical and chemical effects may alter the structure of other subcellular structures such as proteins, nucleic acid, and spindle fibers. Unfortunately, few definite examples can be listed. The action of colchicine and podophyllin in interfering with cell division is well known. The effect of various lactones (coumarin, parasorbic acid, and protoanemonin) on mitotic activity was discussed above. Disturbances to cytoplasmic and vacuolar structure, and the morphology of mitochondria imposed by protoanemonin, were also mentioned. Interference with protein configuration and loss of biological activity was attributed to incorporation of azetidine-2-carboxylic acid into mung bean protein in place of proline. 

Active caspases 8, 9 and 10 can convert caspase-3, the most abundant effector caspase from its pro-form to its active cleaved form. Cleavage of a number of different substrates by caspase-3 and also by caspase-6 and -7 which are two other executioner caspases besides caspase-3 then results in the typical morphology which is characteristic of apoptosis. Yet, the activation of caspase-3 and also of caspase-9 can be counteracted by IAPs, so called inhibitor of apoptosis proteins. However, concomitantly with cytochrome C also other proteins are released from mitochondria, including Smac/DIABLO. Smac/DIABLO and potentially other factors can interact with IAPs and thereby neutralize their caspase-inhibitory activity. This releases the breaks on the cell death program and allows apoptosis to ensue. 

The biflagellate unicellular green alga Chlamydomonas reinhardtii is prone to spontaneous mutations that produce deficiencies in flagellar proteins and MT assembly, substructure, and function. Viable mutants that are either nonmotile or slow moving can be isolated and analyzed biochemically and morphologically, thereby establishing structure-function correlations. Electron microscopic analysis... 

The ER has a reticular morphology which provides a large surface area, which presumably is required for the synthesis and transport of proteins and lipids and for the storage of calcium. The ER is associated with microtubules, and the two are highly interdependent structures. Terasaki et al. (1986) found that when microtubules in the cell are depolymerized by colchicine, the ER network slowly retracts toward the center of the cell. If the microtubules are repolymerized, the ER network is restored to its original morphology, thereby suggesting that the MTs participate in the formation and maintenance of the ER. 

Prior to the study by Chen et al. (140), only one publication discussed the use of the protein casein as a drug carrier (141). Chen et al. systematically compared the many features of albumin and casein microspheres—morphology, drug (adriamycin) incorporation, and release—in an effort to identify important factors in the antitumor effect of this delivery system. 

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